MOD that will help a posting competition??

[Cloverfield]

Okay, soon, I'm about to start a posting compeition on my forum. I was wondering if there was MOd of some kind that would note down what every members post count is (when you specify it to start recording) and then, say, 2 weeks later, you can turn it off and it will tell you how many posts each of those members got in the 2 weeks? Because if there isn't, my job will get a lot harder because I will have to ask everyone to reply in a thread what their current post count it and chances are by the time the competition starts, it will have changed, or some members won't be on for a few days and will forget to post in the thread etc. So I'm just after a MOD that will be able to tell me how many posts every member has got in 2 weeks. Is there such a mod or one similar???